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The next deep Web
EDITOR’S DISPATCH
BY KEVIN Mc CANEY
W ith the right equipment, you can get Internet access
from pretty much anywhere on the surface of the Earth,
from Death Valley to Mount Everest. Below the surface though,
specifically under water, it’s a much different story.
Water poses a problem for wireless communications
because it interferes with radio waves. As a result, underwater
communication systems like those used by the Navy have
often relied on sound waves or very low radio frequencies with
low data rates, such the frequencies between 3 and 30 kilohertz
used in submarine communications. There’s no Internet down
there, no broadband wireless, no GPS navigation.
But could there be? The Defense Advanced Research Projects
Agency wants to find out, with separate projects aimed at
exploring the possibilities for an underwater Internet as well as
a GPS-like constellation that would operate under the sea.
For the first project, the agency is looking for technologies
that would allow submerged manned and unmanned systems
to operate together just like they do on the surface and in the
air—and communicate with airborne systems as well. The goal
is to extend the network below the surface, unencumbered by
water.
The second project, Positioning System for Deep Ocean
Navigation, or POSYDON, aims to seed the ocean floor with
acoustic signaling sources that would work similarly to GPS
satellites, so that submerged vehicles could get precise
positioning information without having to surface. Currently,
submerged vessels use inertial measurement units and
other dead-reckoning sensors to calculate their positions on
short-term missions, but eventually have to surface to get an
accurate GPS reading.
Of the two, the underwater Internet is the more far-reaching,
since it’s looking for some technologies that haven’t been
invented yet. It’s so nascent, in fact, that DARPA, known for
ginning up clever acronyms (like POSYDON) for its projects,
hasn’t even given it a name yet.
But there has been some progress. Researchers sponsored by
the National Institutes of Health, for example, have tested using
the 2.4 GHz ISM frequency band in an underwater environment
(wireless data transmits between 2.4 GHz or 5 GHz).
There is still a long way to go, and considering the
challenges, an underwater Internet could prove to be a pipe
dream. But then again, the Internet itself, not to mention
worldwide wireless and GPS navigation, was once a pipe
dream too.
DefenseSystems.com | MAY/JUNE 2015 9
The science of sweat
Smartphone apps that monitor health and fitness
are increasingly popular, from devices used to
monitor specific diseases, like diabetes, to those
that keep track of weight or exercise. The Air
Force Research Lab is on the verge of going one
better, with a system that tracks many of the
same biomarkers as a blood test, but does it by
monitoring sweat. The system uses a sensor that
looks like a Band-Aid, which collects a sample of
a person’s perspiration and relays that information
wirelessly to a smart phone. AFRL, working
with the University of Cincinnati’s Novel Devices
Laboratory, started on the project five years ago
and recently completed the first successful test of
its prototype. Researchers say the app could have
a significant impact for all of the military services,
since it provides a way to monitor hydration, heat
stress and other factors that can affect the health
and performance of service personnel.
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5/11/15 12:35 PM